[Mesa-dev] [PATCH v2 05/12] anv: Make the clear address 64 bytes aligned.

[Rafael Antognolli]

On Gen10+, if we use the clear state address field in the surface state
instead of the clear color directly, there's a restriction that the
address must point to the lower part of a 64 byte cache-line. So we add
a padding to the state buffer to make it align to 64 bytes when multiple
LOD is present. The clear state address is at the beginning of the
buffer, so it will be aligned as well.

v2: Trying to improve commit message.

Signed-off-by: Rafael Antognolli <rafael.antognolli at intel.com>
---
 src/intel/vulkan/anv_private.h | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/intel/vulkan/anv_private.h b/src/intel/vulkan/anv_private.h
index ed711e9434b..029e1b2b0b8 100644
--- a/src/intel/vulkan/anv_private.h
+++ b/src/intel/vulkan/anv_private.h
@@ -2470,7 +2470,17 @@ anv_fast_clear_state_entry_size(const struct anv_device *device)
     * GPU memcpy operations.
     */
    assert(device->isl_dev.ss.clear_value_size % 4 == 0);
-   return device->isl_dev.ss.clear_value_size + 4;
+
+   const unsigned entry_size = device->isl_dev.ss.clear_value_size + 4;
+   /* On Gen10+, we use the clear color address of the surface to point to this
+    * buffer directly. However, according to the bspec:
+    *
+    *    The memory layout of the clear color pointed to by this address is a
+    *    value stored in the lower-order bytes of a 64-byte cache-line.
+    *
+    * So add some padding here for Gen10+.
+    */
+   return device->info.gen >= 10 ? ALIGN(entry_size, 64) : entry_size;
 }
 
 static inline struct anv_address
-- 
2.14.3